On Wednesday, more than 200 followers of Ms Sanderson's blog urged her to keep fighting against the decision.
But some wrote that writing online carried the same responsibility as any other form of communication.
Raising daughter
The 33-year-old says she never named her company in her internet diary, and although she posted a picture of herself on her weblog, had remained anonymous.
She says her firm also objected to her using office time to write her blog.
In her blog, www.petiteanglaise.com, she mainly writes about her home life raising a three-year-old daughter in Paris.
But she has also posted several messages about her office, describing one of her bosses as "very old school" with a "plummy Oxbridge accent".
Catherine says she started blogging just over two years ago "on a whim".
The blog has built up a sizeable following since then, with some 3,000 readers daily.